1. Field of the Invention
The invention relates to a manipulating apparatus with a first linear shaft, comprising two parallel individual axis elements, where the first linear shaft includes a double slider, which slider runs on the profiles of the two individual axis elements, wherein the double slider is coupled with a drive means of the first single shaft and runs without drive means on the profile of the second single shaft. The invention also relates to a method for the manipulation of workpieces with such apparatus.
2. Brief Description of the Background of the Invention Including Prior Art
A manipulating device of the above-recited general kind is known. Assembly robots are employed in manipulation technology, where one or several "axes" are employed in order to perform motions along several coordinate axes or around these coordinate axes with grippers, tools, or the like. The term "axes" means in the context of the present invention either linear axis elements or rotary axis elements i.e. devices which can be actuated by external forces, which induce a motion along a straight line or around an axis, i.e. essentially a motion confined to a particular topological path.
Piston cylinder units, are usually employed in the case of linear axis elements. Piston-rod-less piston-cylinder units are prevailing in modern manipulator technology. Such piston-cylinder units without piston rods are units, where usually a pneumatic and double-acting piston runs in a cylinder tube. The piston is connected at the two front faces with a belt, a rope or the like. The belt runs along the cylinder axis, is lead outside of the cylinder via seals, is deflected by deflection rollers, and is connected at the outside of the unit with a slider. The slider runs along the outside of the cylinder and thus moves opposite to the piston. An axis element is a structure allowing to perform or performing a motion in an axial direction disposed parallel to an axis.
Solely based on such piston-rod-less linear axis elements, it is possible to build mounting and assembly robots or general manipulating devices of different types and kinds. The linear units are connected to each other at their cylinder heads or sliders, wherein the linear axis elements are disposed at an angle of 90.degree. relative to each other, such that mounting and assembly or manipulating procedures can be performed along a multitude of cartesian coordinates. In this context, a combination of rotation axes is of course also possible such that additional polar coordinates can be taken into consideration in the control of the device.
It is understood that, in addition to piston-rod-less piston cylinder units, piston cylinder units with piston rod or profile slider units with gear belt drives or spindle drives can also be employed as linear axes.
If the first linear axis element is combined with a second linear axis element such that the two axis elements form an angle of 90.degree. relative to each other, and if the first axis element is spatially fixed with its cylinder head, for example, in the kind of a portal frame, then the second linear axis element, running perpendicular to the first linear axis element, operates as an extension. This holds in particular in those cases where the second axis element is attached with its slider on the first axis element and is directed horizontally.
If, in this case, the second axis element, operating as an extension arm, is loaded at its free end, i.e. the cylinder-head, with a heavy tool piece, then there result substantial bending moments. These bending moments are transferred via the long lever arm of the extended second axis element and the connection of the two sliders together onto the longitudinal profile of the first axis element. Such bending moments load the guides of the slider of the first axis element onto the cylinder in a first axial direction can result in damages.
Therefore, it is known from the initially recited manipulating device to let the second linear axis element, operating as an extension arm, not only run on one single first linear axis element, but to subdivide this second linear axis element into two individual axis elements, which are disposed parallel and at a distance relative to each other. Then a double-slider runs on these two individual axes, which double slider carries the slider of the second linear axis element acting as an extension arm. In this way, the rotary moment, acting on the guide structures of the two individual axis elements of the first linear axis element, can be drastically reduced also in case of high loads of the second axis element. Only the double-slider needs to be driven on one of the two individual axis elements in order to obtain a motion of the double-slider on the individual axes of the first linear axis element, while the double slider is merely mechanically guided on the second individual axis element and runs on the second individual axis element without any specific drive associated with the second individual axis element.
It is a goal of modern manipulating and robot technology to be able to perform complex manipulating and assembly processes with a minimum number of axis elements. For this purpose an automatic assembly apparatus for electronic printed circuit boards represents a typical example. Such printed circuit boards, as is known, are equipped with device components of the most varying types and shapes. In order to achieve this, a particular gripper is required for each kind of device element. This gripper is tuned and adapted to the special shape of the device element to be operated such as round, square, rectangular, cylindrical, or the like. Thus, for the complete inserting and equipping of such printed circuit boards a plurality of axis elements has to be employed, wherein each axis element can be furnished with an assembly gripper, which is suitable for a certain kind of device components. Each of these assembly grippers, however, has to be able to pass over the area of the printed circuit boards along two cartesian coordinates, in order to be able to contact each surface position of the printed circuit board with the respective device component.
An unsolvable goal conflict results in this context for conventional manipulating and assembly apparatus, because on the one hand a plurality of complex motion processes with necessarily a plurality of axis elements is required and on the other hand it is desired to perform this procedure within a minimum space.